9291
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 13120
- Proper Divisor Sum (Aliquot Sum)
- 3829
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5832
- Möbius Function
- -1
- Radical
- 9291
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 34
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of 5-tuples of different integers from [ 2,n ] with no common factors among quadruples.at n=18A015645
- First row of spectral array W(e-1).at n=21A022161
- a(n) = Sum_{i=1..floor((n+1)/4)} a(2*i-1) * a(n-2*i+1), with a(1)=a(2)=1 and a(3)=3.at n=16A024725
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 95.at n=23A031593
- a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 4.at n=16A049899
- Leading diagonal of A083173.at n=37A083174
- Number of regions in an equilateral triangular figure formed by the straight line segments connecting all vertices and all points that divide the sides into n equal parts.at n=8A092867
- Numbers n such that 2^n+25229 is prime.at n=52A103148
- Let M be the matrix defined in A111490. Sequence gives M(2,1)-M(1,2), M(2,1)+M(3,1)+M(3,2)-M(1,2)-M(1,3)-M(2,3), etc.at n=43A123329
- Expansion of q / (chi(-q) * chi(-q^3) * chi(-q^5) * chi(-q^15)) in powers of q where chi() is a Ramanujan theta function.at n=39A123632
- Secondary diagonal of A139755, the table of q-derangement numbers of type A.at n=8A141754
- Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-0111-1100 pattern in any orientation.at n=17A146678
- Numbers n whose square can be represented as a repdigit number in some base less than n.at n=41A158235
- Numbers k such that 12*k - 5, 12*k - 1, 12*k + 1, and 12*k + 5 are primes.at n=41A174372
- Coefficient of x in the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=15A192959
- G.f. satisfies: A(x) = Sum_{n>=0} x^n*(A(x)^n + A(-x)^n)/2.at n=12A196195
- Number of n X 1 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.at n=39A201618
- Numbers k such that 4^k - 5 is prime.at n=33A217348
- Numbers n such that n^8+8 and n^8-8 are prime.at n=12A239503
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 630", based on the 5-celled von Neumann neighborhood.at n=26A269543